class ProgressBar

# File lib/progressbar.rb, line 15
def initialize (title, total, out = STDERR)
  @title = title
  @total = total
  @out = out
  @terminal_width = 80
  @bar_mark = "o"
  @current = 0
  @previous = 0
  @finished_p = false
  @start_time = Time.now
  @previous_time = @start_time
  @title_width = 14
  @format = "%-#{@title_width}s %3d%% %s %s"
  @format_arguments = [:title, :percentage, :bar, :stat]
  clear
  show
end

# File lib/progressbar.rb, line 215
def clear
  @out.print "\r"
  @out.print(" " * (get_term_width - 1))
  @out.print "\r"
end

# File lib/progressbar.rb, line 231
def file_transfer_mode
  @format_arguments = [:title, :percentage, :bar, :stat_for_file_transfer]
end

# File lib/progressbar.rb, line 221
def finish
  @current = @total
  @finished_p = true
  show
end

# File lib/progressbar.rb, line 227
def finished?
  @finished_p
end

# File lib/progressbar.rb, line 239
def format= (format)
  @format = format
end

# File lib/progressbar.rb, line 243
def format_arguments= (arguments)
  @format_arguments = arguments
end

# File lib/progressbar.rb, line 247
def halt
  @finished_p = true
  show
end

# File lib/progressbar.rb, line 252
def inc (step = 1)
  @current += step
  @current = @total if @current > @total
  show_if_needed
  @previous = @current
end

# File lib/progressbar.rb, line 268
def inspect
  "#<ProgressBar:#{@current}/#{@total}>"
end

# File lib/progressbar.rb, line 235
def long_running
  @format_arguments = [:title, :percentage, :bar, :stat_for_long_run]
end

# File lib/progressbar.rb, line 259
def set (count)
  if count < 0 || count > @total
    raise "invalid count: #{count} (total: #{@total})"
  end
  @current = count
  show_if_needed
  @previous = @current
end

# File lib/progressbar.rb, line 89
def bytes
  convert_bytes(@current)
end

# File lib/progressbar.rb, line 72
def convert_bytes (bytes)
  if bytes < 1024
    sprintf("%6dB", bytes)
  elsif bytes < 1024 * 1000 # 1000kb
    sprintf("%5.1fKB", bytes.to_f / 1024)
  elsif bytes < 1024 * 1024 * 1000  # 1000mb
    sprintf("%5.1fMB", bytes.to_f / 1024 / 1024)
  else
    sprintf("%5.1fGB", bytes.to_f / 1024 / 1024 / 1024)
  end
end

# File lib/progressbar.rb, line 149
def do_percentage
  if @total.zero?
    100
  else
    @current  * 100 / @total
  end
end

# File lib/progressbar.rb, line 140
def elapsed
  elapsed = Time.now - @start_time
  sprintf("Time: %s", format_time(elapsed))
end

# File lib/progressbar.rb, line 145
def eol
  if @finished_p then "\n" else "\r" end
end

# File lib/progressbar.rb, line 102
def eta
  if @current == 0
    "ETA:  --:--:--"
  else
    elapsed = Time.now - @start_time
    eta = elapsed * @total / @current - elapsed;
    sprintf("ETA: %s", format_time(eta))
  end
end

# File lib/progressbar.rb, line 113
def eta_running_average
  now = Time.now

  # update throughput running average
  if @total > 0 && @eta_previous && @eta_previous_time
    current_elapsed = @current - @eta_previous
    alpha = 0.9 ** current_elapsed
    current_progress = 1.0 * current_elapsed
    current_throughput = current_progress / (now - @eta_previous_time)
    if @eta_throughput
      @eta_throughput = @eta_throughput * alpha + current_throughput * (1-alpha)
    else
      @eta_throughput = current_throughput
    end
  end

  @eta_previous = @current
  @eta_previous_time = now

  if @eta_throughput && @eta_throughput > 0
    eta = (@total - @current) / @eta_throughput;
    sprintf("ETA: %s", format_time(eta))
  else
    "ETA:  --:--:--"
  end
end

# File lib/progressbar.rb, line 41
def fmt_bar
  bar_width = do_percentage * @terminal_width / 100
  sprintf("|%s%s|",
          @bar_mark * bar_width,
          " " *  (@terminal_width - bar_width))
end

# File lib/progressbar.rb, line 48
def fmt_percentage
  do_percentage
end

# File lib/progressbar.rb, line 52
def fmt_stat
  if @finished_p then elapsed else eta end
end

# File lib/progressbar.rb, line 60
def fmt_stat_for_file_transfer
  if @finished_p then
    sprintf("%s %s %s", bytes, transfer_rate, elapsed)
  else
    sprintf("%s %s %s", bytes, transfer_rate, eta)
  end
end

# File lib/progressbar.rb, line 56
def fmt_stat_for_long_run
  if @finished_p then elapsed else eta_running_average end
end

# File lib/progressbar.rb, line 68
def fmt_title
  @title[0,(@title_width - 1)] + ":"
end

# File lib/progressbar.rb, line 93
def format_time (t)
  t = t.to_i
  sec = t % 60
  min  = (t / 60) % 60
  hour = t / 3600
  sprintf("% 3d:%02d:%02d", hour, min, sec);
end

# File lib/progressbar.rb, line 158
def get_term_width
  if ENV['COLUMNS'] =~ /^\d+$/
    ENV['COLUMNS'].to_i
  elsif (RUBY_PLATFORM =~ /java/ || (!STDIN.tty? && ENV['TERM'])) && shell_command_exists?('tput')
    %xtput cols`.to_i
  elsif STDIN.tty? && shell_command_exists?('stty')
    %xstty size`.scan(/\d+/).map { |s| s.to_i }[1]
  else
    DEFAULT_WIDTH
  end
rescue
  DEFAULT_WIDTH
end

# File lib/progressbar.rb, line 172
def shell_command_exists?(command)
  ENV['PATH'].split(File::PATH_SEPARATOR).any?{|d| File.exists? File.join(d, command) }
end

# File lib/progressbar.rb, line 176
def show
  arguments = @format_arguments.map {|method|
    method = sprintf("fmt_%s", method)
    send(method)
  }
  line = sprintf(@format, *arguments)

  width = get_term_width
  if line.length == width - 1
    @out.print(line + eol)
    @out.flush
  elsif line.length >= width
    @terminal_width = [@terminal_width - (line.length - width + 1), 0].max
    if @terminal_width == 0 then @out.print(line + eol) else show end
  else # line.length < width - 1
    @terminal_width += width - line.length + 1
    show
  end
  @previous_time = Time.now
end

# File lib/progressbar.rb, line 197
def show_if_needed
  if @total.zero?
    cur_percentage = 100
    prev_percentage = 0
  else
    cur_percentage  = (@current  * 100 / @total).to_i
    prev_percentage = (@previous * 100 / @total).to_i
  end

  # Use "!=" instead of ">" to support negative changes
  if cur_percentage != prev_percentage ||
      Time.now - @previous_time >= 1 || @finished_p
    show
  end
end

# File lib/progressbar.rb, line 84
def transfer_rate
  bytes_per_second = @current.to_f / (Time.now - @start_time)
  sprintf("%s/s", convert_bytes(bytes_per_second))
end